Cystolith mineral crystals are found in:

Generally,the cells of the cortex lack $.....$.

Which of the following vascular bundles are always open?

$I.$ Phloem transports the food materials usually from the leaves to other parts of the plant.
$II.$ Phloem in the angiosperm is composed of sieve tube elements,companion cells,phloem parenchyma,and phloem fibres.
Identify which of the following statements is correct and select the correct option.

The waxy substance secreted by epidermal cells on their outer walls is:

$I.$ Protection of internal tissues
$II.$ Protection of leaves from microbes
$III.$ Gaseous exchange
$IV.$ Reduction in the rate of transpiration through epidermal cells due to trichomes
Which of the functions of the epidermis is/are relevant from the above-given statements?